This invention relates to improved sawmill methods and apparatus, and more particularly relates to an improved sawmill design and operating concept. In addition, the invention relates to a novel sawmill concept wherein improved methods and apparatus are provided for performing certain of the various functions now performed in sawmills of conventional design.
It is well known that trees are harvested to provide lumber and wood pulp, and that such felled trees are carried to sawmills for this purpose after being de-topped and delimbed, and perhaps also debarked. It is also well known that the sawlogs are sliced into lumber, railroad ties or timbers, and the like, by longitudinally carrying them to and from a revolving circular saw. It is further well known to provide mechanical devices for moving and handling the sawlogs in the sawmill, and also to provide other such devices for moving and handling the lumber and timbers which are produced. What is not well known is that, because of economic and social changes occurring during the past few decades, a need has arisen for a different type of sawmill. More particularly, what is required is a sawmill which is simpler, easier, cheaper and much quicker to erect and put into operation, which is also operable with a minimum number of persons, which is simpler and easier to maintain and repair, and which may be conveniently disassembled for removal and re-erection at another operating site.
A sawmill may be characterized as a system wherein certain functions or steps in a process are performed. The initial point in the process may be considered to be the "log deck" where sawlogs are positioned in a manner such that they may be taken, one at a time, to be cut into lumber and the like. Thus, a "nose section" is preferably provided between the log deck and the carriage and saw section for the purpose of selecting and transferring each sawlog to the carriage which travels back and forth between a revolving circular saw blade.
When a slice is taken from a sawlog or cant which is secured on the carriage, it may be either a board or timber, or it may be a so-called "slab" which is useless for purposes of providing lumber. It is desirable to segregate different pieces at the time they are cut from the sawlog, and thus means is preferably provided for depositing a slab on a first conveyor section leading to a chipper or the like, and for depositing lumber and timber-sized pieces on two or more other different conveyors leading, respectively, to lumber and railroad tie "decks."
It will be apparent from the foregoing that the typical sawmill is a large and complex system which is expensive and time-consuming to install and put into operation. However, the cost and complexity of sawmills has been greatly enhanced, during recent years, by the need to mechanize as much of the operation as possible. This, in turn, has resulted in making sawmills relatively permanent installations, which is inconsistent with an inherent need to be moved, from time-to-time, to move convenient sites. Accordingly, the many small, relatively portable sawmills of the past have now been largely replaced by a proportionately fewer number of much larger and relatively permanently installed sawmills which are, in turn, completely dependent on a transportion system which can accumulate and supply sawlogs from a side area.
Accordingly, there has long been a need for a mechanical sawmill which requires a minimum number of personnel to operate, but which is also capable of being erected in a shorter length of time, which can be disassembled and removed to another operating site without effectively being destroyed as an operating unit, and which is simpler and therefore easier and cheaper to maintain. The various features and techniques which are employed to provide the large sawmills of the prior art are inherently inconsistent with providing all of these features in the same operating unit, and thus simplicity and portability have accordingly been sacrificed in favor of mechanization.
These disadvantages of the prior art are overcome with the present invention, and novel sawmill methods and apparatus are herewith disclosed for providing a sawmill which is operable with a minimum number of persons, which is relatively simple and quick to erect and put into operation at a substantially lower cost, which may be easily disassembled and reassembled at a new location, and which further includes improved and novel component sections for performing various of the aforementioned functions or steps.